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<html lang="zh-CN">
	<head>
		<meta charset="UTF-8" />
		<meta name="author" content="wangbo" />
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		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
		<title>Document</title>
	</head>
	<body>
		<script>
			let num = 10
			let istrue = true
			let obj = { name: '张三' }
			let str = '我的名字'
			let mynull = null
			let myundefined = undefined
			let arr = [1, 2, 3]
			console.log(typeof num)
			console.log(typeof istrue)
			console.log(typeof str)
			console.log(typeof mynull)
			console.log(typeof myundefined)
			console.log(typeof obj)
			console.log(typeof arr)

			console.log(obj instanceof Object)
			console.log(arr instanceof Array)
      
			console.log(Object.prototype.toString.call(num))
			console.log(Object.prototype.toString.call(istrue))
			console.log(Object.prototype.toString.call(str))
			console.log(Object.prototype.toString.call(mynull))
			console.log(Object.prototype.toString.call(myundefined))
			console.log(Object.prototype.toString.call(obj))
			console.log(Object.prototype.toString.call(arr))




		</script>
	</body>
</html>
